1. Field
Embodiments of the present invention relate to peripheral component interconnects and, in particular, to peripheral component interconnect (PCI) bus protocol.
2. Discussion of Related Art
A peripheral component interconnect (PCI) local bus is a bus in a computer system that interconnects a microprocessor and peripheral devices, such as keyboards, disk drives, video adapters, etc. A PCI bus has slots into which the adapter cards for the peripheral devices can be inserted or removed. The PCI Local Bus Specification, Revision 3.0, Feb. 3, 2004, PCI Special Interest Group, Portland, Oreg., (hereinafter “PCI Specification”) provides, among other things, the protocol(s) and configuration specification for PCI Local Bus components and adapter cards. Products designed by different vendors but which are compatible with the PCI Specification also may be compatible with each other.
The PCI Express™ Base Specification, Revision 1.0a, Apr. 15, 2000, PCI Special Interest Group, Portland, Oreg., (hereinafter “PCI Express Specification”), along with PCI Special Interest Group (hereinafter “PCI-SIG”) Engineering Change Notice (hereinafter “ECN”) of Aug. 21, 2003 and the ECN of Jan. 21, 2004, provide for an enhancement of the PCI Specification. As the PCI Express Specification describes, a PCI Express to PCI Bridge provides a connection between a PCI Express fabric and a PCI hierarchy. Traditional PCI Express to PCI Bridges have limitations, however.